The subject of the invention is a suppressor of gas pressure fluctuation and noise for inlet and outlet systems of machines operating in cycles with a working medium is gas, and especially for an inlet oil injection inlet system of a positive displacement air compressor.
Cyclic operation of positive-displacement machines generates pressure fluctuations which, particularly in an inlet system, may cause a considerable decrease of the volumetric efficiency of the machine and an increased power demand for compression. Besides, the inlet system emits noise, mainly of aerodynamic origin, of a relatively high sound intensity level. Disadvantageous effects of those phenomena are minimized by application of various types of suppressors to the inlet and outlet systems of such machines.
For example the type of system for suppressing pressure fluctuation and noise of compressors presented in Polish patent specification No. 118 094 comprises a suppressor in a cylindrical housing which contains a chamber with an eccentrically fixed tubular suppressing element. The outlet tube is situated on the side surface, in the plane perpendicular to the axis of the suppressor, dividing the chamber into two equal parts, and oriented according to the axis transecting the axes of the chamber and the suppressing element. Air flows into the suppressor through the tubular suppressing element, wherefrom it gets out through a longitudinal slot situated on the wall of the element, most closely to the housing of the suppressor. Eccentric location of the suppressing element forms in the space of the chamber a system of two symmetrical nozzles through which air flows to the outlet tube. Owing to such design, pressure fluctuation and noise are advantageously suppressed, but hydraulic resistance, patricularly at high flow velocities, significantly affect the filling efficiency, capacity and power demand for compression.
Some positive-displacement machines, especially compressors with oil injection at the inlet, for example according to Polish patent application No. P-212 219, are characterized, for the reason of a very short piston stroke in relation to the lateral dimension, by a strong dependence on flow resistance at the inlet. In such conditions, when we strive at dynamically supercharging the compressor, which, entails an unfortunate increase of the intensity level of aerodynamic-origin noise emitted to the environment, designing of a pressure-fluctuation and noise suppressor which also provides for low flow resistance is a particularly significant technical problem.